Die extractor

ABSTRACT

A TOOL FOR EXTRACTING A DIE FROM A MOUNTING RECESS IN A HOLDER, HAVING A THRUST MEMBER ENGAGABLE WITH THE HOLDER ADJACENT TO THE RECESS, AN EXTRACTION DEVICE ENGAGEABLE WITH THE DIE, AND REACTION POWER STRUCTURE OPERABLE ON AND BETWEEN THE MEMBER AND THE DEVICE TO EFFECT DIE-EXTRACTING MOVEMENT OF THE DEVICE RELATIVE TO THE THRUST MEMBER TO WITHDRAW THE DIE FROM THE RECESS AS THE MEMBER THRUSTS AGAINST THE DIE HOLDER.

Oct, 12, 1971 N, JR 3,611,539

DIE EXTRACTOR Filed June 16,, 1969 United Smtes Patent 3,fill,539 Patented Get. 12, 1971 3,611,539 DIE EXTRACTOR John A. Meaden, Jr., 635 S. Park, Hiusdale, Ill. 60521 Filed June 16, 1969, Ser. No. 833,358

Int. Cl. B23p 19/04 US. Cl. 29-253 Claims ABSTRACT OF THE DISCLOSURE This invention relates to a die extractor, and more particularly to a tool for extracting a die from a mounting recess in a holder.

Certain types of dies, such as those employed in sheet punching and like equipment are mounted in respective recesses in a holder. For example, in one such arrangement the holder is in the form of a roll or wheel witha series of the dies mounted in respectlve recesses in the perimeter of the holder. Since it is necessary to have the dies held quite accurately so as to effect accurate registration with complementary punches to be received in respective holes providing shearing edges on the dies, a very close fit of the dies in the recesses is desirable. As a result, the dies frequently resist withdrawal from the recesses in the holder. Nevertheless, it may be necessary from time to time to replace the dies, such as when it is desired to punch holes of different size in a production run of sheets. However, especially with dies of the inverted cup-shape with central shear edge holes, it is difiicultto effect engagement with an outer surface of the respective dies to effect removal. While a hook-shaped extracting rod or lever may be employed for dislodging the' dies, resistance is often encountered greater than ordinary manual effort can overcome. Further, in applying manual effort to such an extracting device it may be levered against and damage the shearing edge.

According to the principles of the present invention the foregoing problem is efiiciently overcome by a tool which has a thrust member engageable with the die holder adjacent to the die-mounting recess, an extraction device engageable with the die, and reaction power structure operable on and between the member and the device to effect die-extracting movement of the device relative to the thrust member as the thrust member thrusts against the die holder to withdraw the die from its recess or socket.

An important object of the present invention is to provide a new and improved die extractor which will efiiciently and positively draw a die from a socket recess in a holder in an efiicient, positive, manner avoiding any damage to the die.

Another object of the invention is to provide new and improved means for extracting dies from sockets in holders by straight-out pulling force.

A further object of the invention is to provide a new and improved means for extracting dies from sockets by engagement with normally hidden shoulder surfaces of the dies while avoiding damage to shearing edges of the dies.

Still another object of the invention is to provide a new and improved positively acting, simple and rugged tool for extracting dies from socket recesses in die holders.

Other objects, features and advantages of the invention will be readily apparent from the following description of a preferred embodiment thereof, taken in conjunction with the accompanying drawings, although variations and modifications may be effected without departing from the spirit and scope of the novel concepts of the disclosure, and in which:

FIG. 1 is a side elevational view on a small scale of a tool embodying features of the invention;

FIG. 2 is an enlarged vertical sectional detail View through the tool taken substantially on the line 11-11 of FIG. 1 and showing the same applied in a preliminary manner to a tool holder for extracting a die therefrom;

FIG. 3 is a similar vertical sectional detail view demonstrating the tool in operation with the die partially extracted;

FIG. 4 is a lower end view of the tool in the ready condition shown in FIG. 2; and

FIG. 5 is a similar end view of the tool showing the same with the die-gripping device expanded.

In the illustrated embodiment of the invention, a tool 10 is constructed and arranged for extracting dies 11 of the type mounted in respective socket recesses 12 in a die holder 13. This holder may be in the form of a roller or Wheel mounting a series of the dies 11 coactively relative to a complementary punch holder (not shown). In this instance each of the dies 11 has a generally inverted cupshape provided with a cylindrical. body closely received within the socket 12 which is of complementary cylindrical shape and has an inner or root surface 14 against which the die is seated, with a punching debris dropout passage 15 leading therefrom in alignment with a die hole 17 in the dome-shaped outer end of the die providing a shearing edge cooperating with a punch to be received operatively in the hole. Retention. of the die in the holder in service is effected by means of a retaining screw 18.

To extract the die 11 from the socket 12, the tool 10 has a thrust member 19 which is engageable with the holder 13 adjacent to the recess socket 12, an extraction device 20 engageable with the die 11, and reaction power structure 21 operable on and between the thrust member 19 and the extraction device 20 to effect die-extracting movement of the device 20 relative to the thrust member 19 to withdraw the die from the socket as the member 19 thrusts against the die holder. In a simple, rugged, easily manipulated construction, the thrust member 19 comprises a sleeve having a thrusting end 22 to engage the holder 13 about the outer end of the socket recess 12 and is of larger internal diameter than the recess so as to be capable of receiving the die 11 therein during the extracting operation.

In a simple manner of attaining strong reaction power, the structure 21 comprises a generally cylindrical elongated barrel received within the member 19 and having a suitably threaded outer perimeter 23 in threaded engagement with a threaded inner perimeter 24 of the member 19. Through this arrangement the barrel 21 can be reciprocally moved relative to the member 19 by turning the barrel which is provided with means such as hexagonally arranged wrench faces 25 on an outer end head portion 27 thereof to facilitate turning the same. In order to facilitate holding the thrust member 19 stationary while the barrel 21 is turned, the outer perimeter of the member 19 is desirably provided with Wrench faces 28.

According to the present invention, the extraction device 20 comprises means for entering the die hole 17 3 and engaging an inner, normally inaccessible shoulder surface of the die 11 and more particularly such surface adjacent to the hole 17 on the domed, roof portion of the die. For this purpose, the extraction device 20 comprises a longitudinally split head 29 normally held in contracted condition by an encircling contractile spring 30. This head seats on reaction shoulder means comprising an annular inturned flange 31 at the inner end of the barrel element 21 which is tubular in form for this purpose. Desirably the head 29 has its outer end tapered to extend through a clearance hole 32 defined by the flange 31 and which is of desirably larger diameter than the die hole 17. Extending centrally from the tapered portion of the head 29 is a die-entering neck 33 which in the contracted condition of the extraction head is of substantially smaller diameter than the die hole 17. On its outer end portion, the split neck 33 has a laterally projecting shoulder flange 34 which in the collapsed condition of the head clears freely through the die opening 17 (FIGS. 2 and 4). Through this arrangement, when it is desired to extract the die 11, the tool is placed to intrude the neck 33 through the die hole 17.

After the tool has been placed with the neck 33 in the die hole 117, the extraction device head 29 is expanded to place the shoulder flange 34 in gripping relation to the inner shoulder surfaces about the die aperture 17. This is effected by means comprising an expander pin 35 which extends down within a funnel-like recess 37 in the head 29 and terminates in a progressively stepped expansion bore 38 extending on through the neck 33 and of sufficiently smaller diameter than the expander pin 35 to effect the desired die-gripping expansion of the neck 33 when the pin 35 is driven longitudinally into the neck. To facilitate such driving the pin is provided with a tapered cam tip 39.

Actuation of the pin 35 is effected by easily manipulated means comprising an operating plunger 40 with the inner end of which the pin may be coaxially integral, while the outer end of the plunger has a knurled digitally operable knob or head 41. Peripherally the plunger 40 is provided with threads 42 along a substantial length thereof and which are engaged with complementary internal threads on the barrel member 21. Normally, the plunger 40 is maintained in a retracted position, as shown in FIG. 2 wherein thepin 35 is similarly retracted relative to the head 29 so that the head is collapsed (FIGS. 2 and 4), thus enabling insertion of the extraction gripper neck 30 into the die aperture 17 Upon threadedly driving the plunger 40 inwardly, the pin 35 progressively expands the head 29 in opposition to bias of the retracting spring 30, until the neck 33 has been fully expanded and the shoulder 34 confronts the opposing shoulder area of the die head about the opening 17 (FIGS. 3 and S).

In order to prevent possible tendency of the head 29 to displace undesirably relative to the barrel flange 31 at any time, a stabilizing and biasing spring 44 of the coiled compression variety is operatively disposed between an inward shoulder 45 on a reduced diameter guide portion 47 of the plunger and the inner end of the head 29. This spring is preloaded to afford at least some pressure on the head when the plunger 40 is backed off into head-releasing relation of the pin 35, and exerts progressively greater biasing thrust on the head as the pin 35 is driven into head-expanding relation by the plunger 40 whereby to counteract any tendency of the head to slip back unduly, or more than necessary relative to the shoulder flange 31 to enable adequate expansion. To avoid overdriving of the plunger, a further reduced diameter portion 48 thereof has a tapered stop surface 49 leading to the base of the pin 35 and confronting in engageable relation with a complementary surface within the recess 37 of the head to stop the plunger at a. pre ferred maximum in-driving position.

After the tool 10 has been placed in an interlocked relation with the die 11 to be extracted, namely, with the extraction neck 33 expanded to place the shoulders 34 in extracting relation to the die, axial extracting power is generated by relatively screwing the thrust member 19 and the barrel 21. This may be done by holding the barrel 21 against turning while relatively turning the member 19 so that the barrel moves out of the member 19 and the flange 31 lifts the expanded head 29 and the shoulders 34 interlocked with the die 11 extract the die from its socket 12 and draw the die into the chamber within the tubular member 19 which is of ample inside diameter to receive the die freely. After the die has been extracted and lifted away from the die holder 13, it is readily released from the tool 10 by manipulation of the plunger 40 to withdraw the pin 35 from the extractor head neck 33 such that the head is collapsed to enable withdrawal of the neck 33 and its shoulder 34 from the die or dropping away of the die as released.

I claim as my invention:

1. In a tool for extracting a die from a mounting socket recess in a holder:

a tubular thrust member engageable at one end with holder about said socket;

a reaction power structure comprising a barrel threadedly engaged and longitudinally threadedly movable in said thrust member and having inturned reaction shoulder means on its end portion adjacent to said one end of the thrust member about an opening therethrough;

an extraction device seated on said shoulder means within said barrel having means projecting through said opening and operable to engage with the die and adapted to interlock therewith; and

means on said barrel and said thrust member enabling threaded turning of the barrel relative to the thrust member to move said shoulder means away from said one end with the device seated thereon to effect die-extracting pull on said projecting means interlocked with the die.

2. Apparatus according to claim 1, wherein said shoulder means comprises an inturned annular flange on the inner end of the barrel.

3. A tool according to claim 2, wherein said device comprises a longitudinally split head having a tapered portion in engagement with said flange with die-engaging means extending therefrom, means normally applying yieldable contracting bias to said head, and expanding means operable in said head to eifect expansion of the head while riding on. said flange to effect interlocking expansion of said die-engaging means into interlocking relation with the die.

4. A tool according to claim 3, said yieldable biasing means comprising a contractile spring encircling said head.

5. A tool according to claim 3, said means for expanding said head comprising a taper-tipped pin engageable between the split portions of the head, and means for operating said pin comprising a plunger carrying the pin and threadedly engaged within said barrel and having an operating knob extending outwardly relative to the barrel.

6. A tool according to claim 5, including compression spring means engaging between said plunger and said head to thrust the head normally toward said flange.

7. A tool according to claim 2, including compression spring means normally thrusting said device toward said flange.

8. A tool according to claim 2, said head being split and having a tapered surface engaging said flange whereby said compression spring means acting against the head normally causes the split portions of the head to be cammed toward one another, and means selectively operative to effect expansion of the split portions of the head accompanied by camming of the head portions on said. flange.

d 9. A tool according to claim 7, including a tapered tip FOREIGN PATENTS pin engageable with and between said head portions, said head portions defining a stepped expansion bore into 1,115,341 12/1955 France 29-463 which said pin is thrustable to expand the head portions 7 423 2 1953 Great i i 29 2 3 relative to one another. 5

10. A tool according to claim 8, including a plunger WILLIAM S LAWSON, Prima Examiner threadedly engaged in said barrel and fixedly carrying said pin, said head defining a recess opening toward said L. GILD'EN, Assistant Examiner plunger, and said plunger having a portion engageable in said recess as a stop upon overdriving of the plunger 10 U S C1, X,R toward the head. 29.463

References Cited UNITED STATES PATENTS 2,373,307 4/1945 Goddard et al. 29-278 X 15 2,380,980 8/1945 Looncy 29263 

